code: def test_subresultants_amv():
      x = var("x")
  
      p = (
          x**8
          + x**6
          - 3 * x**4
          - 3 * x**3
          + 8 * x**2
          + 2 * x
          - 5
      )
      q = 3 * x**6 + 5 * x**4 - 4 * x**2 - 9 * x + 21
      assert subresultants_amv(p, q, x) == subresultants(p, q, x)
      assert subresultants_amv(p, q, x)[-1] == sylvester(p, q, x).det()
      assert subresultants_amv(p, q, x) != euclid_amv(p, q, x)
      amv_factors = [1, 1, -1, 1, -1, 1]
      assert subresultants_amv(p, q, x) == [
          i * j
          for i, j in zip(
              amv_factors, modified_subresultants_amv(p, q, x)
          )
      ]
  
      p = x**3 - 7 * x + 7
      q = 3 * x**2 - 7
      assert subresultants_amv(p, q, x) == euclid_amv(p, q, x)
  
imports: from sympy.core.symbol import var
  from sympy.polys.polytools import pquo, prem, sturm, subresultants
  from sympy.matrices import Matrix
  from sympy.polys.subresultants_qq_zz import sylvester, res, res_q, res_z, bezout, subresultants_sylv, modified_subresultants_sylv, subresultants_bezout, modified_subresultants_bezout, backward_eye, sturm_pg, sturm_q, sturm_amv, euclid_pg, euclid_q, euclid_amv, modified_subresultants_pg, subresultants_pg, subresultants_amv_q, quo_z, rem_z, subresultants_amv, modified_subresultants_amv, subresultants_rem, subresultants_vv, subresultants_vv_2
label_desc: Use image node_id 21 for calling a global function with example usage: test_subresultants_amv() without return types